Appendectomy during pregnancy: rates, safety, and outcomes over a five-year period. A hospital-based follow-up study.

INTRODUCTION: Appendicitis is the most common acute abdominal complication during pregnancy. If appendix perforation occurs there is an increasing risk of preterm delivery and other pregnancy complications. OBJECTIVE: To assess the outcome of pregnancy after appendectomy, the mode of surgery used, appendectomy rates, and complications. METHODS: A prospective cohort study of pregnant women with, or without, appendectomy at South Stockholm General Hospital, December 2015 to February 2021 in a setting where pregnant women are prioritized for surgery and laparoscopic surgery was standard of care in first half of pregnancy. Data on preoperative imaging, surgical method, intraoperative findings, microscopic findings, hospital stay, pregnancy, and 30-day complications were prospectively recorded in a local appendectomy register. A non-pregnant control group was gathered comprising women of fertile age in the same study interval. RESULTS: During the study period 50 pregnant women, of whom 44 gave birth, underwent appendectomy of 38 199 women giving birth. There were no differences between women with or without appendectomy in proportion of preterm delivery (4.5% vs. 5.6%), small-for-gestational age (2.3% vs. 6.2%), or Cesarean delivery (18.2% vs. 20.4%). The rate of appendix perforation was 19% in non-pregnant control group compared to 12% among pregnancy. There was no case of perforated appendix in the second half of pregnancy. However, women with gestational age > 20 weeks more frequently had an unaffected appendix compared to those operated ≤ 20 gestational weeks (4/11 vs. 2/39, p = .005). Laparoscopic surgery was used in 97% of non-pregnant control group, 92% of appendectomies ≤ 20 weeks gestation, and in 27% >20 weeks. As compared to first half, the appendectomy rate was three times lower during the second half of pregnancy. Pregnant women had priority for surgery < 6 h compared to < 24 h among non-pregnant women, this resulted in a shorter time-to-surgery among pregnant women (p < .001). CONCLUSION: Routine laparoscopic surgery and time priority for pregnant surgery is associated with a low risk of perforation, preterm birth and other complications. However, a low threshold for surgery may increase the risk of a negative exploration.

Is out-of-hours cholecystectomy for acute cholecystitis associated with complications?

BACKGROUND: Existing data on the safety of out-of-hours cholecystectomy are conflicting. The aim of this study was to investigate whether out-of-hours cholecystectomy for acute cholecystitis is associated with a higher risk for complications compared with surgery during office hours. METHODS: This was a population-based cohort study. The Swedish Gallstone Surgery and Endoscopic Retrograde Cholangiopancreatography Register (GallRiks) was used to investigate the association between out-of-hours cholecystectomy for acute cholecystitis and complications developing within 30 days. Data from patients who underwent cholecystectomy between 2006 and 2017 were collected. Out-of-hours surgery was defined as surgery commencing between 19.00 and 07.00 hours on weekdays, or any time at weekends (Friday 19.00 hours to Monday 07.00 hours). Multivariable logistic regression analysis was used to assess the risk of complications, with time of procedure as independent variable. The proportion of open procedures and proportion of procedures exceeding 120 min were also analysed. Adjustments were made for sex, age, ASA grade, time between admission and surgery, and hospital-specific features. RESULTS: Of 11 153 procedures included, complications occurred within 30 days in 1573 patients (14·1 per cent). The adjusted odds ratio (OR) for complications for out-of-hours versus office-hours surgery was 1·12 (95 per cent c.i. 0·99 to 1·28). The adjusted OR for procedures completed as open surgery was 1·39 (1·25 to 1·54), and that for operating time exceeding 120 min was 0·63 (0·58 to 0·69). CONCLUSION: Out-of-hours complications may relate to patient factors and the higher proportion of open procedures.

ANTECEDENTES: Los datos existentes sobre la seguridad de la colecistectomía fuera del horario laboral son discordantes. El objetivo de este estudio fue investigar si la colecistectomía para el tratamiento de la colecistitis aguda realizada fuera del horario laboral se asocia con un mayor riesgo de complicaciones en comparación con la cirugía efectuada durante el horario laboral. MÉTODOS: Se trata de un estudio de cohortes de base poblacional. Se utilizó el registro Swedish Gallstone Surgery and Endoscopic Retrograde Cholangiopancreatography Register (GallRiks) para examinar la asociación entre la colecistectomía por colecistitis aguda realizada fuera del horario laboral y las complicaciones a los 30 días. Se recogieron los datos de los pacientes en los que se realizó una colecistectomía entre 2006 y 2017. Se definió como cirugía fuera del horario laboral aquella realizada entre las 19:00 y las 07:00 de lunes a viernes y en cualquier momento durante los fines de semana (de viernes 19:00 a lunes 07:00) Se realizó un análisis de regresión logística multivariable para evaluar el riesgo de complicaciones, considerando la hora de la cirugía como variable independiente. También se analizó el porcentaje de intervenciones por vía abierta y el de aquellas cuya duración excedió de los 120 minutos. Se realizaron ajustes por sexo, edad, puntuación ASA, días desde el ingreso hasta la cirugía y características específicas del hospital. RESULTADOS: Se produjeron 1.573 (14,1%) complicaciones en las 11.153 intervenciones incluidas. La razón de oportunidades, odds ratio (OR) ajustada para las complicaciones comparando la cirugía fuera del horario laboral con la cirugía dentro del horario laboral, fue de 1,12 (i.c. del 95% 0,99-1,28). La OR ajustada para los procedimientos realizado por vía abierta fue de 1,39 (1,25-1,54). La OR ajustada para el tiempo operatorio > 120 minutos fue de 0,63 (0,58-0,69). CONCLUSIÓN: Las complicaciones que suceden en la cirugía efectuada fuera del horario laboral es más probable que se deban a factores relacionados con el paciente que con la hora del día en que se practica la cirugía. Debe tenerse en cuenta que las intervenciones realizadas por vía abierta fuera del horario laboral tienen una mayor morbilidad.

Parastomal Hernia Repair; Seldom Performed and Seldom Reported: Results From a Nationwide Survey.

BACKGROUND: Parastomal hernia is common, but there are few population-based studies showing the frequency and outcome of parastomal hernia repair in routine surgical practice. The aim of this study was to identify patients undergoing surgery for parastomal hernia in Sweden and to define risk factors for complication and recurrence. METHODS: A broad search of the Swedish National Patient Register 1998-2007 for all possible parastomal hernia repairs using surgical procedure codes. Records of all patients identified were reviewed and those with a definite parastomal hernia procedure were included and analyzed. RESULTS: A total of 71 patients were identified after review of the records. The most common reason for surgery was cosmetic and the most frequent method was relocation of the stoma. Parastomal hernia recurrence rate was 18% during follow-up of a minimum 2 years. Overall, a surgical complication occurred in 32%. Possible risk factors were analyzed including emergency surgery versus planned, gender, age, indication for surgery, and method of surgery; none of which was significant. CONCLUSION: The frequency of parastomal hernia procedures was much lower than suggested by previous studies. The number of procedures per surgeon was even lower than expected. No specific risk factor could be identified. Parastomal hernia auditing in the form of a nationwide quality register should be mandatory. Centralization should be considered.

Perirenal fat surface area as a risk factor for perioperative difficulties and 30-day postoperative complications in elective colon cancer surgery.

AIM: Visceral obesity is associated with perioperative and postoperative complications in colorectal surgery. We aimed to investigate the association between the perirenal fat surface area (PRF) and postoperative complications. METHOD: Data on 610 patients undergoing curative, elective colon cancer resection between 2006 and 2016 at Stockholm South General Hospital were retrieved from a local quality register. We assessed perioperative and postoperative outcomes using a multinomial regression model adjusted for age, sex, American Society of Anesthesiologists classification and surgical approach (open/laparoscopy) in relation to PRF. RESULTS: PRF could be measured in 605 patients; the median area was 24 cm2 . Patients with PRF ≥ 40 cm2 had longer operation time (median 223 vs 184 min), more intra-operative bleeding (250 vs 125 ml), reoperations (11% vs 6%), surgical complications (27% vs 13%) and nonsurgical infectious complications (16% vs 9%) than patients with PRF < 40 cm2 , but there were no differences in the need for intensive care or duration of hospital stay. The multivariate analyses revealed an increased risk of any complication [OR 1.68 (95% CI 1.1-2.6)], which was even more pronounced for moderate complications [Clavien-Dindo II, OR 2.14 (CI 1.2-2.4]; Clavien-Dindo III, OR 2.35 (CI 1.0-5.5)] in patients with PRF ≥ 40 vs < 40 cm2 . The absolute risk of complications was similar in men and women with PRF ≥ 40 cm2 . CONCLUSION: PRF, an easily measured indirect marker of visceral obesity, was associated with overall and moderate complications in men and women and could serve as a useful tool in the assessment of preoperative risk.

Time trends, improvements and national auditing of rectal cancer management over an 18-year period.

AIM: The main aims were to explore time trends in the management and outcome of patients with rectal cancer in a national cohort and to evaluate the possible impact of national auditing on overall outcomes. A secondary aim was to provide population-based data for appraisal of external validity in selected patient series. METHOD: Data from the Swedish ColoRectal Cancer Registry with virtually complete national coverage were utilized in this cohort study on 29 925 patients with rectal cancer diagnosed between 1995 and 2012. Of eligible patients, nine were excluded. RESULTS: During the study period, overall, relative and disease-free survival increased. Postoperative mortality after 30 and 90 days decreased to 1.7% and 2.9%. The 5-year local recurrence rate dropped to 5.0%. Resection margins improved, as did peri-operative blood loss despite more multivisceral resections being performed. Fewer patients underwent palliative resection and the proportion of non-operated patients increased. The proportions of temporary and permanent stoma formation increased. Preoperative radiotherapy and chemoradiotherapy became more common as did multidisciplinary team conferences. Variability in rectal cancer management between healthcare regions diminished over time when new aspects of patient care were audited. CONCLUSION: There have been substantial changes over time in the management of patients with rectal cancer, reflected in improved outcome. Much indirect evidence indicates that auditing matters, but without a control group it is not possible to draw firm conclusions regarding the possible impact of a quality control registry on faster shifts in time trends, decreased variability and improvements. Registry data were made available for reference.

Endoscopic diagnosis of acute intestinal GVHD following allogeneic hematopoietic SCT: a retrospective analysis in 175 patients.

Diagnosis of acute intestinal GVHD (aGVHD) following allogeneic hematopoietic cell transplantation is based on clinical symptoms and histological lesions. This retrospective analysis aimed to validate the 'Freiburg Criteria' for the endoscopic grading of intestinal aGVHD. Grade 1: no clear-cut criteria; grade 2: spotted erythema; grade 3: aphthous lesions; and grade 4: confluent defects, ulcers, denudation of the mucosa. Having excluded patients with infectious diarrhea, we evaluated 175 consecutive patients between January 2001 and June 2009. Setting a cutoff between grade 1 (no change in therapy) and grade 2 (intensification of immunosuppression), macroscopy had a sensitivity of 89.2% (95% confidence interval (CI): 80.4-94.9%), a specificity of 79.4% (95% CI: 69.6-87.1%), a positive-predictive value of 79.6% (95% CI: 70.0-87.2%) and a negative-predictive value of 89.0% (95% CI: 80.2-94.9%). In all, 20% of patients with aGVHD in the lower gastrointestinal tract (GIT) had lesions only in the terminal ileum. In all patients with aGVHD ≥2 of the upper GIT, typical lesions were also found in the lower GIT. Ileo-colonoscopy showed the highest diagnostic yield for aGVHD. In conclusion, the 'Freiburg Criteria' for macroscopic diagnosis of intestinal aGVHD provide high accuracy for identifying aGVHD ≥2.

Prevalence of gastroesophageal reflux symptoms in adolescents: is there a difference in different racial and ethnic groups?

The study aims to determine if differences exist among racial/ethnic groups in the prevalence of gastroesophageal reflux symptoms in adolescents. A cross-sectional questionnaire was administered to a sample of students in four racially and ethnically diverse high schools in suburban Chicago. A total of 2561 questionnaires were analyzed: 33% Hispanics, 30% Caucasians, 22% African Americans, 15% Asians, 54% female, mean age 15.8 (±1.3) years. Thirty-two percent had at least one esophageal and/or respiratory symptom ≥once a week. Caucasians and African Americans had more dysphagia than Hispanics and Asians (7% vs. 4%; P= 0.04). Hispanics had more heartburn (13% vs. 9-11%; P= 0.06) but this was not statistically significant. There was no difference for regurgitation. Hispanic females had more dysphagia (6% vs. 3%; P= 0.02) and heartburn (17% vs. 9%; P= 0.0003) than Hispanic males. African Americans and Caucasians had more respiratory symptoms than Hispanics and Asians (29%, 24% vs. 18%; P= 0.000004). Students with esophageal symptoms were more likely to have respiratory symptoms (46% vs. 17%; P < 0.0005). African Americans and Caucasians with esophageal symptoms had more respiratory symptoms than Hispanics and Asians with esophageal symptoms (55%, 49% vs. 42%, 34%; P= 0.0003). Asians and Hispanics were less likely to treat symptoms than African Americans and Caucasians (26%, 33% vs. 47%, 49%; P= 0.001). We found that differences exist among the racial/ethnic groups with esophageal and respiratory symptoms; esophageal symptoms are a risk factor for respiratory symptoms, and Asians and Hispanics seek less medical help. Future research should focus on whether the differences found continue and reasons for them.

Nonmonotonic zero-point entropy in diluted spin ice.

Water ice and spin ice are important model systems in which theory can directly account for "zero-point" entropy associated with quenched configurational disorder. Spin ice differs from water ice in the important respect that its fundamental constituents, the spins of the magnetic ions, can be removed through replacement with nonmagnetic ions while keeping the lattice structure intact. In order to investigate the interplay of frustrated interactions and quenched disorder, we have performed systematic heat capacity measurements on spin ice materials which have been thus diluted up to 90%. Investigations of both Ho and Dy spin ices reveal that the zero-point entropy depends nonmonotonically on dilution and approaches the value of Rln2 in the limit of high dilution. The data are in good agreement with a generalization of Pauling's theory for the entropy of ice.

The Swedish rectal cancer registry.

BACKGROUND: An audit of all patients with rectal cancer in Sweden was launched in 1995. This is the first report from the Swedish Rectal Cancer Registry (SRCR). METHODS: Between 1995 and 2003, 13 434 patients treated for adenocarcinoma of the rectum were registered with the SRCR; there were approximately 1500 new patients annually. RESULTS: Approximately half had an anterior resection, a quarter an abdominoperineal resection and 15 per cent a Hartmann's procedure. The median 30-day postoperative mortality rate was 2.4 per cent and the overall postoperative morbidity rate was 35.0 per cent. The 5-year cancer-specific survival rate was 62.3 per cent. The 5-year relative survival rate was 70.1 per cent after anterior resection, 59.8 per cent after abdominoperineal resection and 39.8 per cent after a Hartmann's procedure. The crude 5-year local recurrence rate was 9.5 per cent overall, 6.1 per cent after preoperative radiotherapy and 11.4 per cent after surgery alone. For 3868 patients who had a locally curative procedure the local recurrence rate was 7.4 per cent overall, 5.9 per cent for those who had radiotherapy and 10.2 per cent for those who did not. The local recurrence rate was 2.9 per cent (28 of 968) for stage I disease, 7.9 per cent (112 of 1418) for stage II, 13.9 per cent (188 of 1357) for stage III and 8.5 per cent (45 of 532) for stage IV. CONCLUSION: These good population-based results are due, in part, to the nationwide prospective quality assurance registration.

Improved survival and reduction in local failure rates after preoperative radiotherapy: evidence for the generalizability of the results of Swedish Rectal Cancer Trial.

OBJECTIVE: The Swedish Rectal Cancer Trial (SRCT) demonstrated that a short-term regimen of high-dose preoperative radiotherapy (5 x 5 Gy) not only reduced the local recurrence rates but also improved the overall survival rate. This compelling evidence will have a significant impact on the primary treatment of rectal cancer. The authors' aim was to explore the representativeness of the study. SUMMARY BACKGROUND DATA: Until the SRCT was presented in 1997, no major trial had established that radiotherapy has a positive effect on the overall survival rate. METHODS: A review of all rectal cancer cases reported to the Swedish Cancer Registry during the same period that the SRCT accrued patients (1987 to 1990) was performed at 57 of 68 participating hospitals. At these 57 hospitals, there were 2366 patients with invasive rectal cancer, with 1664 of these patients fulfilling the criteria for inclusion in the SRCT. RESULTS: Fifty-two percent (866/1664) of eligible patients were included in the SRCT. The patients not included, of whom 8% (67/798) received adjuvant radiotherapy, had an overall 5-year survival rate of 48%, which was identical to the overall survival rate in the SRCT surgery-alone group (48%) but was inferior to the SRCT radiotherapy group (58%). The cancer-specific 5-year survival rates were 65% and 66% among the patients not included and the surgery-alone group, respectively. The local recurrence rates reached 27% in both groups. The results were still comparable when stratifying for curative surgery, tumor stage, and surgical procedure. CONCLUSIONS: The achieved inclusion level of 52% in a randomized multicenter trial is comparatively high. Because the population in the SRCT was representative, it was concluded that the study results are reliable.

Changing strategy for rectal cancer is associated with improved outcome.

BACKGROUND: In 1980, surgery for rectal cancer at the Department of Surgery, Uppsala University Hospital was concentrated to a colorectal unit and a more systematic use of adjuvant radiotherapy began. In 1985, total mesorectal excision was introduced. The aim of this study was to determine whether these changes had an impact on the overall treatment outcome. METHODS: Some 423 consecutive patients with rectal cancer had surgery between 1974 and 1995 and were followed up until 1 January 1998. Outcome analysis was made according to the following predefined intervals of diagnosis: 1974-1979, 1980-1984 and 1985-1995. RESULTS: The overall local recurrence rate was 47 per cent in the first interval, and 13 and 11 per cent during the second and third respectively (P < 0.001). In the third interval, of 119 patients who received preoperative irradiation and underwent radical resection, only three (3 per cent) had locally recurrent rectal cancer. There was improved cancer-specific survival between the first and the last intervals of the study (P = 0.03). CONCLUSION: These data are consistent with the interpretation that the results of treatment can be improved by concentration of surgery to a colorectal team.

[13C-urea breath test as diagnostic method in Helicobacter pylori infection]. / 13C-urea-pusteprøve som diagnostisk metode ved Helicobacter pylori-infeksjon.

We have evaluated a 13C-urea breath test for the diagnosis of Helicobacter pylori infection. The 13C-test was analyzed with isotope-selective nondispersive infrared spectrometry and compared with a 14C-urea breath test and the urease test in gastric mucosal biopsies. 46 patients were analyzed with breath tests; 23 patients were negative and 22 patients were positive with both methods. One patient was positive with the 14C-method and negative with the 13C-urea breath test. 61 patients were analyzed with the 13C-urea breath test and the urease test. 30 patients were negative and 30 patients were positive with both methods, whereas one patient with a negative urease test had a positive breath test. 13C-urea breath test analyzed with isotope-selective non-dispersive infrared spectrometry is a fast, simple, non-radioactive, non-invasive, convenient and reliable method for the diagnosis of Helicobacter pylori infection.

Improved survival in patients with rectal cancer: a population-based register study.

BACKGROUND: Between 1985 and 1989, only one centre in Sweden combined preoperative radiotherapy with total mesorectal excision (TME) in the primary treatment of rectal cancer. The aim of this study was to investigate whether this change in primary treatment had an impact on the outcome. METHOD: The survival rate of 94,262 patients with colorectal cancer from the total Swedish population between 1960 and 1989 was analysed. RESULTS: A continuous improvement in relative survival rate occurred during the first year of follow-up for both colonic and rectal cancer. Some improvement was also seen during follow-up years 2-5, but this was much more pronounced during the last period (1985-1989) for rectal cancer in the county of Uppsala. The improvement was particularly marked during follow-up years 3-5. CONCLUSION: There are strong indications from this study that altered primary treatment for rectal cancer results in improved long-term survival.

Preoperative irradiation affects functional results after surgery for rectal cancer: results from a randomized study.

PURPOSE: The Swedish Rectal Cancer Trial has unequivocally demonstrated that preoperative high-dose (5 x 5 Gy) radiotherapy reduces local failure rates and improves overall survival. This will have an impact on the primary treatment of rectal cancer. This study investigates the effect of preoperative high-dose radiotherapy on long-term bowel function in patients treated with anterior resection. METHODS: A questionnaire was answered by 92 percent (203/220) of patients who were included in the Swedish Rectal Cancer Trial and who were alive after a minimum of five years. Thirty-two patients were excluded, mainly because of postoperative stomas and dementia, which left 171 for analysis. RESULTS: Median bowel frequency per week was 20 in the irradiated group (n = 84) and 10 in the surgery-alone group (n = 87; P < 0.001). Incontinence for loose stools (P < 0.001), urgency (P < 0.001), and emptying difficulties (P < 0.05) were all more common after irradiation. Sensory functions such as "discrimination between gas and stool" and "ability to safely release flatus" did not, however, differ between groups. Thirty percent of the irradiated group stated that they had an impaired social life because of bowel dysfunction, compared with 10 percent of the surgery-alone group (P < 0.01). CONCLUSIONS: The study indicates that high-dose radiotherapy influences long-term bowel function, thus emphasizing the need for finding predictive factors for local recurrence to exclude patients with a very high probability for cure with surgery alone and to use optimized radiation techniques.

Clinicopathological staging and management of colorectal cancer. Perioperative radiation therapy.

The use of radiotherapy, as a complementary procedure prior to surgery for immobile, nonresectable, rectal cancers or as an adjuvant treatment in patients with mobile rectal cancer is discussed. Locally nonresectable rectal cancer can be resected after prolonged preoperative radiotherapy. The proportion of patients possible to cure after this prolonged treatment is not precisely known, mainly due to differences in the criteria for nonresectability. Literature data show that between 35% and 80% can undergo resection for cure, and 25% to 40% can be long-term disease-free survivors. Moreover, the role of chemotherapy in combination with radiotherapy in this group is not yet settled owing to the lack of convincing data from randomized trials. Data from the literature clearly indicate that preoperative radiotherapy in patients with mobile rectal cancer is superior to postoperative irradiation. Provided the dose is sufficiently high, a relative reduction in the local recurrence rate of 60% in combination with "standard surgery" is to be expected, and this reduction increases long-term survival. An important question is the role of adjuvant radiotherapy together with "more optimized surgery." It is likely that the local recurrence rate will decrease with the same magnitude, indicating that local recurrent rectal cancer in patients with mobile rectal cancer can be more or less eradicated if optimized surgery is combined with preoperative radiotherapy. With proper timing and treatment technique, the adverse effects on surrounding tissues, both immediate and late, can be kept acceptably low.

Short-term preoperative radiotherapy results in down-staging of rectal cancer: a study of 1316 patients.

BACKGROUND AND PURPOSE: This study was undertaken to investigate down-staging effects after short-term, high-fractionated preoperative radiotherapy. MATERIAL AND METHODS: The relationships between preoperative radiotherapy 25-25.5 Gy given over 5-7 days and clinical variables (sex, age, tumour level, metastatic disease, and tumour size) and the risk of lymph node metastases were examined in 1316 patients with rectal adenocarcinoma by uni-, and multivariate analyses. RESULTS: Irradiated specimens contained smaller tumours (P < 0.00001) and nodal metastases were less common (P < 0.001). In a logistic regression model, tumour size in cm was positively related to the risk for nodal spread (odds ratio, OR = 1.14, 95% confidence limits, CL, of OR 1.08-1.22). In the same model, radiotherapy decreased the risk for nodal involvement (OR 0.73, 95% CL 0.58-0.92. This risk was particularly reduced when the time interval between start of radiotherapy and surgery equalled 10 days or more. CONCLUSIONS: These results demonstrate a down-staging effect by a short course of preoperative radiotherapy which should be considered in the interpretation of radiotherapy trials and in the recruitment of patients for further postoperative adjuvant treatment.

Improved survival with preoperative radiotherapy in resectable rectal cancer.

BACKGROUND: Adjuvant radiotherapy for rectal cancer has been extensively studied, but no trial has unequivocally demonstrated improved overall survival with radiotherapy, despite a reduction in the rate of local recurrence. METHODS: Between March 1987 and February 1990, we randomly assigned 1168 patients younger than 80 years of age who had resectable rectal cancer to undergo preoperative irradiation (25 Gy delivered in five fractions in one week) followed by surgery within one week or to have surgery alone. RESULTS: The irradiation did not increase postoperative mortality. After five years of follow-up, the rate of local recurrence was 11 percent (63 of 553 patients) in the group that received radiotherapy before surgery and 27 percent (150 of 557) in the group treated with surgery alone (P<0.001). This difference was found in all subgroups defined according to Dukes' stage. The overall five-year survival rate was 58 percent in the radiotherapy-plus-surgery group and 48 percent in the surgery-alone group (P=0.004). The cancer-specific survival rates at nine years among patients treated with curative resection were 74 percent and 65 percent, respectively (P=0.002). CONCLUSIONS: A short-term regimen of high-dose preoperative radiotherapy reduces rates of local recurrence and improves survival among patients with resectable rectal cancer.

Evaluation of HemoCue Blood Glucose Analyzer for the instant diagnosis of hypoglycaemia in newborns.

The aim of the study was to evaluate a portable photometer, HemoCue Blood Glucose Analyzer, in the instant diagnosis of hypoglycaemia in newborns. The HemoCue is a simple, easy-to-handle photometer; with an analysis time of less than 240 s, it utilizes a modified glucose dehydrogenase method in 5 microliters whole blood. The HemoCue method was compared to a hexokinase method for deproteinized whole blood in a total of 118 samples from 58 newborns. The linear regression for these samples was Y = 1.19 x -1.02 (range 0.7-7.2 mmol/L), r = 0.90. Ten samples were < or = 2.0 mmol/L with both methods and 37 samples were < or = 2.0 mmol/L with the HemoCue method. The average difference (D) for each sample (n = 118) and the standard deviation (SD) for the difference were 0.45 +/- 0.46 mmol/L. Blood samples with a mean value with both methods < or = 2.0 mmol/L (n = 20) had a D and SD of 0.71 +/- 0.29 mmol/L. When testing for linearity at low glucose concentrations, the HemoCue method gave significantly lower values compared to an ideal line. The HemoCue method has several advantages in the analysis of glucose in newborns: short analysis time, small sample size, and no influence from glycolysis. However, in our investigation, falsely low values occurred, especially in the low measuring range, so the HemoCue method is not suitable in the diagnosis of hypoglycaemia in newborns.

An automated C4b binding protein assay compared with an electroimmunoassay in a clinical material.

We have evaluated an automated, simplified, turbidimetric method for the measurement of the C4b binding protein (C4bBP). A comparison with a manually performed electroimmunoassay in plasma samples referred for coagulation analysis (n = 80) revealed a correlation coefficient of 0.88. Lipaemic plasma is not suitable for analysis, whereas moderately haemolytic or icteric plasma may be used with the present method. In young and middle-aged patients (n = 33) investigated 3 or more months after an episode with thrombosis of unknown reason, the mean C4bBP concentration was not significantly different from the mean found in healthy controls (n = 38). This result is in accordance with the hypothesis that C4bBP is an acute phase reactant. The results indicate that the turbidimetric assay may replace the electroimmunoassay in clinical work.

Kinetic characterization of the polymerase and exonuclease activities of the gene 43 protein of bacteriophage T4.

The DNA polymerase from the bacteriophage T4 is part of a multienzyme complex required for the synthesis of DNA. As a first step in understanding the contributions of individual proteins to the dynamic properties of the complex, e.g., turnover, processivity, and fidelity of replication, the minimal kinetic schemes for the polymerase and exonuclease activities of the gene 43 protein have been determined by pre-steady-state kinetic methods and fit by computer simulation. A DNA primer/template (13/20-mer) was used as substrate; duplexes that contained more single-strand DNA resulted in nonproductive binding of the polymerase. The reaction sequence features an ordered addition of 13/20-mer followed by dATP to the T4 enzyme (dissociation constants of 70 nM and 20 microM) followed by rapid conversion (400 s-1) of the T4.13/20-mer.dATP complex to the T4.14/20-mer.PPi product species. A slow step (2 s-1) following PPi release limits a single turnover, although this step is bypassed in multiple incorporations (13/20-mer-->17/20-mer) which occur at rates > 400 s-1. Competition between correct versus incorrect nucleotides relative to the template strand indicates that the dissociation constants for the incorrect nucleotides are at millimolar values, thus providing evidence that the T4 polymerase, like the T7 but unlike the Klenow fragment polymerases, discriminates by factors > 10(3) against misincorporation in the nucleotide binding step. The exonuclease activity of the T4 enzyme requires an activation step, i.e., T4.DNA-->T4.(DNA)*, whose rate constants reflect whether the 3'-terminus of the primer is matched or mismatched; for matched 13/20-mer the constant is 1 s-1, and for mismatched 13T/20-mer, 5 s-1. Evidence is presented from crossover experiments that this step may represent a melting of the terminus of the duplex, which is followed by rapid exonucleolytic cleavage (100s-1). In the presence of the correct dNTP, primer extension is the rate-limiting step rather than a step involving travel of the duplex between separated exonuclease and polymerase sites. Since the rate constant for 13/20-mer or 13T/20-mer dissociation from the enzyme is 6 or 8 s-1 and competes with that for activation, the exonucleolytic editing by the enzyme alone in a single pass is somewhat inefficient (5 s-1/(8 s-1+5 s-1)), ca. 40%. Consequently, a major role for the accessory proteins may be to slow the rate of enzyme.substrate dissociation, thereby increasing overall fidelity and processivity.